Hi guys - welcome to the cat box. Where are you based?

Someone is bound to tell you, sooner or later, that harmonising shanties is "not traditional". Well, "traditional" shanty singers mostly also had scurvy and the clap - you can take "traditional" too far. On board ship, when shanties were used to co-ordinate work, there obviously weren't any formal, "worked out" harmonies, but people's voice ranges differ and there would have been plenty of natural harmonies (and less pleasant noises) as everyone tried to sing together. Most shanty crews here in the UK seem to work mainly on that basis (hopefully without the less-pleasant noises, most of the time). I remember one bass singer with a well-known crew being asked at a workshop to "sing one of his bass lines" and replying that he couldn't, without someone else singing the melody. He just heard the harmonies when others were hearing the tune.

At the end of the day, it's a matter of what works for you and what sort of sound you want to produce. Have fun. If it sounds good, you're doing it right.

Andrew
Crane Drivin' Music